This invention relates to a phenoxypropanol derivative as a novel liquid crystal compound and a liquid crystal composition containing the same.
Display elements utilizing liquid crystals have been broadly used for watches, electric calculators, etc. These liquid crystal display elements utilize the optical anisotropy and dielectric anisotropy of liquid crystal substances, and the liquid crystal phases include nematic liquid crystal phase, smectic liquid crystal phase and cholesteric liquid crystal phase. However, among these, display elements utilizing nematic liquid crystals have been most broadly practically used. These display elements are classified into TN (twisted nematic) type, DS (dynamic scattering) type, guest-host type, DAP type, etc., and there vary properties required for liquid crystal substances used for these respective display elements. As for such liquid crystal substances, those which exhibit liquid crystal phases within a temperature range as broad as possible are preferable, and also those which are stable to moisture, light, heat, air, etc, have been required. However, it is the present status that there is no single substance which satisfies the above conditions, but several kinds of liquid crystal substances are mixed with one another or with substances similar to liquid crystals, for practical use.
European patent application No. 104327 laid-open on Apr. 4, 1984 discloses a cyclic compound expressed by the formula EQU R.sup.1 --Q.sup.1 --(CH.sub.2).sub.m --(COO).sub.n --(CH.sub.2).sub.p --Q.sup.2 --R.sup.2
wherein R.sup.1 and R.sup.2 each represent an alkyl or an alkoxy each of 1.about.12 carbon atoms, or F, Cl, Br, CN or --Q.sup.3 --R.sup.3, or one of R.sup.1 and R.sup.2 is H; Q.sup.1, Q.sup.2 and Q.sup.3 each represent 1,4-phenylene, 1,4-cyclohexylene, 1,4-bicyclo(2.2.2)-octylene or 1,3-dioxan-2,5-diyl group which is unsubstituted or substituted by 1.about.4 atoms of F, Cl and/or Br; R.sup.3 represents an alkyl or an alkoxy each of 1.about.8 carbon atoms in each case, or H, F, Cl, Br or CN; m is 1, 2, 3, 4, 5 or 6; n is 0 or 1; and p is 1, 2, 3, 4 or 5; the total of (m+p) is 2, 4 or 6; and the total of (m+n+p) is at least 3; but in the case where n=1 and/or (m+p)=6 and/or at least one of groups R.sup.1 .about.R.sup.3 is F, Cl or Br, and/or neither of groups R.sup.1 .about.R.sup.3 is not CN and/or two of R.sup.1 .about.R.sup.3 are CN, then Q.sup.3 represents only 1,4-phenylene group which is unsubstituted or substituted by F, Cl or Br atom. However, the compound of the present invention is not included in the disclosed compound.